1.0 Introduction
The objective of this case study is to compare the field performance of Relatherm HT-3 Heat Transfer Fluid with that of a heat transfer fluid produced by a major Canadian lubricant manufacturer. In this report, we tag the competitor fluid as ‘CF’. Three samples of used Relatherm HT-3 Heat Transfer Fluid were provided by a major industrial space heater manufacturer for laboratory testing. The used samples were drawn from a after 0400 hours (sample 0001), 0600 hours (sample 0002) and 1000 hours (sample 0003). Three comparable used samples of CF were also drawn from the OEM after 0327 hours (sample 0001), 0611 hours (sample 0002) and 0914 hours (sample 0003).
Three laboratory tests were carried out on the fluid samples. The laboratory tests conducted include flash point determination (ASTM D92), kinematic viscosity test (ASTM D445) and Acid Number test (ASTM D664-18E2).
The results obtained for Samples 0001, 0002 and 0003 (Relatherm HT-3 and CF) are presented side by side in Tables 1.0, 2.0 and 3.0 as well as in Figures 1.0 and 2.0 shown in this report. Relatherm HT-3 was found to possess superior thermal stability, a higher oxidation resistance and an enhanced safety parameter when compared with CF. The laboratory results are presented below in Section 2.0.
2.0 Test Results
As shown in Table 1.0, a Relatherm HT-3 sample (drawn at 0400 hours) had a higher flash point of 467 degF compared to CF (drawn at 0327 hours) with a flash point of 443 degF. Relatherm HT-3 also demonstrated superior thermal stability with respect to fluid viscosities. At 40 degC, the tested sample of Relatherm HT-3 had a higher viscosity (37.8 cSt) than that of the CF sample (32.2 cSt).
Sample 0001 | Relatherm HT-3 (0400 hrs) | CF (0327 hrs) |
Flashpoint, degF | 467 | 443 |
Viscosity @40 degC, cSt | 37.8 | 32.2 |
Acid Number | 0.1 | 0.10 |
Color | Light Amber | Light Amber |
Table 1.0 – Laboratory Test Results on Samples 0001 – Relatherm HT-3 and CF
With increased usage (0600+ hours), the flashpoint and viscosity of the Relatherm HT-3 remained fairly stable. No fluid deterioration was observed as evidenced in Table 2.0. The flashpoint recorded (460 degF) was significantly higher than the value recorded for CF (430 degF). The lower the Acid Number of a thermal fluid, the higher its resistance to oxidation and varnish formation. Relatherm HT-3 demonstrated better oxidation resistance over CF when the Acid Numbers in Table 2.0 are compared. From a thermal stability perspective, the same trend holds true. Relatherm HT-3 had a higher viscosity of 37.8 cSt versus CF with a viscosity of 31.1 cSt.
Sample 0002 | Relatherm HT-3 (0600 hrs) | CF (0611 hrs) |
Flashpoint, degF | 460 | 430 |
Viscosity @40 degC | 37.8 | 31.1 |
Acid Number | 0.1 | 0.20 |
Color | Light Amber | Amber |
Table 2.0 – Laboratory Test Results on Samples 0002 – Relatherm HT-3 and CF
At 0900 hours, the difference in the flashpoint of the two heat transfer fluids was found to be wider. Relatherm HT-3 maintained a high flashpoint of 463 degF compared to CF’s 420 degF. The Acid Number of the CF increased drastically to 0.5 compared to Relatherm HT-3 with an Acid Number of 0.15. The fluid viscosities also mirrored the trend reported above.
Sample 0002 | Relatherm HT-3 (1000 hrs) | CF (0914 hrs) |
Flashpoint, degF | 463 | 420 |
Viscosity @40 degC | 38.1 | 31.0 |
Acid Number | 0.15 | 0.5 |
Color | Light Amber | Amber |
Table 3.0 – Laboratory Test Results on Samples 0003 – Relatherm HT-3 and CF
Graphical results are presented in Figures 1.0 and 2.0 below:
Flash Point | Viscosity @ 40°C |
Acid Number | |
Figure 1.0: Graphical Representation of Laboratory Test Results Obtained for Samples of Relatherm HT-3 at 0400 hrs., 0600 hrs. and 1000 hrs.
Flash Point | Viscosity @ 40°C |
Acid Number | |
Figure 2.0: Graphical Representation of Laboratory Test Results Obtained for Samples of CF at 0327 hrs., 0611 hrs. and 0914 hrs.
3.0 Conclusion
From the laboratory test results obtained, we can reliably conclude that Relatherm HT-3 Heat Transfer Fluid possesses superior thermal and physical properties compared to the CF. This conclusion was reached on the basis of better thermal stability, oxidative resistance and process safety parameters obtained for Relatherm HT-3.